/Engine/Source/Editor/Sequencer/Public/SequencerTimeSliderController.h
If we are dragging a scrubber or dragging to set the time range
enum DragType { DRAG_SCRUBBING_TIME, DRAG_SETTING_RANGE, DRAG_PLAYBACK_START, DRAG_PLAYBACK_END, DRAG_SELECTION_START, DRAG_SELECTION_END, DRAG_MARK, DRAG_NONE, }